Posters
- Impact of inhomogeneous reionization on post-reionization 21 cm intensity mapping measurement of cosmological parameters
- Black Hole Binaries with Natal Kicks
- Stellar populations and emission lines in S-PLUS galaxies.
- Didactic proposal for a comparative meteorology course between Earth and Mars.
- Studying the Tensions in the Standard Cosmological Model Using Alternative Cosmological Tracers.
- BETIS: Bidimensional Exploration of the warm-Temperature Ionized gaS.
- Structure, kinematics and time evolution of the Galactic Warp revealed by Classical Cepheids.
- Morphological Study of Spiral Galaxies with Multiple Arms.
- Spectroscopic analysis of the open clusters IC 2391 and NGC6475.
- Determination of physical parameters of near-Earth asteroids by the Gauss method and lightcurves.
- Identify stars proper to cluster to know the evolution of the Small Magellanic Cloud.
- Analysis of Hypercompact HII Region Candidate.
- In Search for Angular Momentum in Molecular Outflows using High-Angular Resolution Maser Observations.
- Stellar populations and emission lines in S-PLUS galaxies.
- Characterization of the arms of the galaxy M83 from the study of the field of individual stars.
- Structure and Kinematics of an Accretion Jet-Disk system.
Heyang Long, Catalina Morales-Gutiérrez, Paulo Montero-Camacho, and Christopher M. Hirata.
ABSTRACT: 21 cm intensity mapping (IM) has the potential to be a strong and unique probe of cosmology from redshift of order unity to redshift potentially as high as 30. For post-reionization 21 cm obsevations, the signal is modulated by the thermal and dynamical reaction of gas in the galaxies to the passage of ionization fronts during the Epoch of Reionization. In this work, we investigate the impact of inhomogeneous reionization on the post-reionization 21 cm power spectrum and the induced shifts of cosmological parameters at redshifts at the redshift range 3.5 to 5.5. We make use of hydrodynamics simulations that could resolve small-scale baryonic structure evolution to quantify H I abundance fluctuation, while semi-numerical large box 21CMFAST simulations capable of displaying inhomogeneous reionization process are deployed to track the inhomogeneous evolution of reionization bubbles. We find the inhomogeneous reionization effect could impact the H I power spectrum up to tens of percent level and shift cosmological parameters estimation from sub-percent to tens percent in the observation of future post-reionization 21 cm intensity mapping experiments SKA-LOW and PUMA. In particular, the shift is up to 0.033 in the spectral index ns and 0.025 eV in the sum of the neutrino masses depending on the reionization model and the observational parameters. We discuss strategies to mitigate and separate these biases.
Edwin Santiago-Leandro, Clarissa Áviles and Aldo Batta
ABSTRACT: The observation of over 90 Gravitational Wave (GW) events by the LIGO-Virgo-KAGRA (LVK) collaboration, has yielded information of the merger of compact object binaries, such as their individual masses and spins. However, the effective spin parameter obtained from the GW signal provides important information that could be used to discern the binary's formation channel. Overall, binaries formed from dynamic interactions in dense stellar environments are expected to have a random distribution of effective spins between -1 and 1. Meanwhile, binaries formed from the evolution of isolated stellar binaries are expected to have positive effective spins unless there is a large enough natal kick during the compact object formation that could significantly alter the orientation of the individual spins with respect to the binary's angular momentum. The objective of this work is to study the viability of obtaining large natal kicks during the formation of massive BHs by studying the asymmetric mild explosion of $21\text{M}_{\odot}$ and $28\text{M}_{\odot}$ pre-supernova stellar models, by means of 3D Smooth Particle Hydrodynamics simulations. The question we want to answer is if it is likely, or even possible, to form natal kicks capable of producing negative effective spins. Our preliminary results show either smaller or higher values for the final velocity of the black hole than the reduced velocity expected from BH mass accretion, depending on the energy of the explosion. Our preliminary results show either smaller or higher values for the final velocity of the black hole than the reduced velocity expected from a spherically symmetric accretion of mass and momentum, depending on the energy of the explosion.
J. Thainá-Batista, R. Cid Fernandes, S-PLUS team.
ABSTRACT: We present tests of a new method to simultaneously estimate stellar population and emission line (EL) properties of galaxies out of S-PLUS photometry. The method uses the AlStar code, updated with an empirical prior which greatly improves its ability to estimate ELs using only the survey’s 12 bands. The tests compare the output obtained from (noise-perturbed) synthetic photometry of SDSS galaxies to properties derived from previous full spectral fitting and detailed EL analysis. We find that, for realistic signal-to-noise ratios, stellar population properties are recovered to better than 0.2 dex in masses, mean ages, metallicities and ±0.2 mag for the extinction. More importantly, ELs are recovered remarkably well for a photometric survey. We obtain input-output dispersions of 0.05–0.2 dex for the equivalent widths of [O II], [O III], H𝛽, H𝛼, [N II], and [S II], and even better for lines stronger than ∼ 5 Å. This is achieved by exploring two facts: (1) Because, for the redshifts explored here, H𝛼 and [N II] fall in a narrow band (J0660), their combined equivalent width is always well recovered, even when [N II]/H𝛼 is not. (2) We know from the SDSS that 𝑊H𝛼+[N II] correlates with [N II]/H𝛼 and thus can be used to diagnose if a galaxy belongs to the left or right wing in the classical BPT diagnostic diagram. We combine these two facts in a prior which restricts the EL-space available for the fits, obtaining excellent results. Example applications to integrated light and spatially resolved data are also presented.
Raidel Sosa Armas.
ABSTRACT: In Cuba, meteorology as a science has been studied since 1965. Currently, the development of this science is one of the strengths of our academics. However, meteorological knowledge in the island is limited to the study of weather and climate on our planet, leaving aside the fact that: while the study of meteorology on Earth can be done without studying other planets, the comparative study of planets allows us to it can help identify many physical processes that interact to produce the planet's climate and to contribute to its change. This work consists of a didactic proposal of a comparative meteorological weather course between Mars and Earth. For it, a varied bibliography was consulted in this regard, including the current meteorology program, which allows the new course to be synchronized with the current one. It is also presented in this course how the climate of our planet evolves in the current conditions of the planet Mars.
Bianca Gonzalez and Ricardo Chavez Murillo.
ABSTRACT: In recent years, various cosmological models have been proposed to explain the origin and large-scale structure formation of the universe. One prominent model is the standard cosmological model, ΛCDM (Lambda Cold Dark Matter), which posits that the cosmological constant, related to dark energy, is responsible for the accelerating expansion of the universe. This model also adheres to the cosmological principle, asserting that the universe is spatially homogeneous and isotropic on large scales. A crucial aspect of this model is the study of its cosmological parameters, particularly the Hubble constant, which describes the relationship between the recession speed of galaxies and their distance. Measurements of the Hubble constant obtained from the Cosmic Microwave Background and Baryonic Acoustic Oscillations data differ from those derived from standard candles such as supernovae, cepheids, and HII galaxies, resulting in a tension of at least 4σ. The cause of this discrepancy remains unclear; however, accurately determining the Hubble constant is essential for obtaining precise distances to extragalactic objects. The primary objective of this project is to accurately determine cosmological parameters by meticulously scrutinizing potential systematic errors linked to data obtained from a diverse range of cosmological tracers. These tracers encompass the Cosmic Microwave Background, Baryonic Acoustic Oscillations, Type Ia supernovae, as well as HII regions and galaxies. To accomplish this, a Bayesian statistical analysis is used, enabling a deeper understanding of both statistical and systematic uncertainties associated with each tracer, ultimately enhancing the overall reliability of the derived parameters.
R. González-Díaz, F. Fabián Rosales-Ortega, Lluís Galbany.
ABSTRACT: Understanding the relationship between stellar formation processes and the interstellar medium (ISM) is a key step in discerning the complexity in the evolutionary history of galaxies. A problem in this regard has been understanding the nature and importance of feedback processes in which massive stars deposit energy into the interstellar medium through photoionization, stellar winds, and supernovae. This feedback mechanism affects the physical and dynamic state of the ISM and therefore has an influence on the rate and distribution of stellar formation in galaxies. In this context, the existence of a warm and ionized component of the ISM that is ubiquitously distributed in galaxy disks has been known for decades. In our work, we define a sample of 265 galaxies observed with the MUSE IFS instrument of the VLT-8.1m telescope to perform a spectral and spatial analysis of the Diffuse Ionized Gas (DIG), in order to explore the distributions the low-ionization species [OIII], [OI], [NII] and [SII] in the DIG regimes along the galactic planes, as well as discern the different ionization mechanism that result in this gas. We create a methodology based on the creation of emission line maps from the MUSE datacubes after performing a SSP synthesis to every spaxel. We also elaborate an adaptive binning method to increase the signal-to-noise ratio of the lower surface brightness lines such as [OIII], [OI] and [SII].
Mauro Cabrera-Gadea, Cecilia Mateu, Pau Ramos, Mercè Romero-Gomez, Teresa Antoja and Luis Aguilar.
ABSTRACT: In this work, we present a new characterisation of the warped disc traced by Cepheids. Cepheids are young (<500 Myr) and luminous standard candles, excellent for mapping the structure of the thin disc of the Milky Way. With a Fourier decomposition of their vertical height and vertical velocity, we found that the S-type warp traced by Cepheids has a maximum amplitude of 1.1 kpc, presents a more extended and wrapped line of nodes than previously known and is followed by a wrapped line of maximum vertical velocity that trails behind by 25 a result that challenges several warp models. We also found asymmetries in the warp structure that change with the radius, showing a more symmetrical warp in the outskirts of the disc than previous work reported. Finally, we develop a new formalism to obtain the warp pattern speed as a function of the radius, showing a constant pattern speed of 10.5 km/s/kpc, in agreement with previous works.
Jose Mauricio Diaz Fonseca and Nelson Vera Villamizar.
ABSTRACT:Spiral galaxies show qualities in their morphology, and their evolutionary processes are of great interest to the astronomical community. The conditions that allow the formation of discoidal galaxies with spiral structure remain unclear. Additionally, each spiral galaxy is unique in the universe, but they can be classified based on distinct morphological characteristics, including grand-design galaxies, galaxies with multiple arms, and flocculent galaxies. While each class of grand-design and flocculent galaxies has its own theories of evolution and origin, the formation theories specifically addressing the spiral structure in multiple-armed galaxies have not been extensively explored, and the existing theories for grand-design galaxies are typically applied in such cases. To expand the studies on spiral galaxies with multiple arms, this work aims to identify morphological characteristics in this type of galaxy. To achieve this, we employ the two-dimensional Fourier transform method and propose a technique to quantify the importance of modes in the radial distribution of the disk and detect the presence of symmetric or fragmented spiral structures. Using radial density functions, we generate synthetic images of galaxies to confirm the effectiveness of the method for analyzing spiral structures in discoidal galaxies. Through this technique, it becomes evident that it is not possible to consider a galaxy as having multiple arms or grand design throughout its entire disk. The multiple-arm structures detected in this study are found only in certain regions of the radius. For a set of galaxies, it is observed that multiple-arm structures are located in the inner regions of the disk, near the nucleus, while in another group, the spiral structure is present in the intermediate or outer regions of the disk.
Angela Catalina Franco Becerra, Orlando Katime Santrich and Nelson Vera Villamizar.
ABSTRACT: Open clusters are important astrophysical objects to study the stellar evolution theory as well as to investigate the structure of the galactic disk. Our sample is composed of FGK stars, dwarfs and giants within open clusters IC2391 and NGC6475. We have selected high-resolution spectra with SNR >150 from the FEROS ESO/archive. We have applied the LTE hypothesis to derive the stellar atmospheric parameters (effective temperature Teff , surface gravity log g, metallicity [Fe/H] and micro-turbulent vellocity) and chemical abundances of the alpha and neutron-capture elements. The first results confirm that three stars (IC 2391-44 IC 2391-SHJM6 IC 2391-SHJM2) are in main sequence phase whereas other two (NGC 6475-58 NGC6475-134) in RGB-phase. Our abundances confirm that the sample falls along the galactic chemical evolution trend. show that our chemical abundances are similar to the abundances of FGK stars in the the Galactic disk and that our stars are on the main sequence and RGB-phase. The cluster IC 2391 is the one with the greatest dispersion among its stars when the abundance ratios are analyzed, in addition to this, the abundances of its alpha elements are at the limit within the trend reported for field giants and open clusters studied by (Luck, 2015). It is also evident that this cluster is poor in elements of the s-process when we compare it with the other clusters of the sample, the field giants and the clusters analyzed by (Luck, 2015).This fact is also reflected in the low value of the indicators spectroscopic age when we compare it with the other objects of study. These results indicate that the cluster is most likely within the inner disk of the Milky Way and that his training took place in an environment that was poorly contaminated by previous generations of stars. The spread in the abundances of the stars NGC647558 and NGC6475134 are minimal, therefore from the spectroscopic analysis analyzed we can affirm that the star NGC647558 must be within the cumulus. The abundances of its alpha elements and proceso-s corroborate that the accumulation is within the trend marked by the inner galactic disk.
José B. Batista, Eduardo Chung.
ABSTRACT: The problem of preliminary or initial orbit determination (IOD) of minor planets is important to astronomy since dozens of new asteroids are discovered every year. Detecting asteroids and calculating their orbits makes it possible to warn if they are potentially hazardous asteroids (PHA). This study deals with the parameterization of near-Earth asteroids (NEA) by means of Gauss’ classical IOD method, complemented by photometric analysis through their respective light curves. Specifically, the NEAs in this study are 5626 Melissabrucker, 11405 (1999 CV3), 28609 Tsirvoulis, 66251 (1999 GJ2), 107757 (2001 FK37), 161989 Cacus and 206318 (2003 MN10). This required gathering data over at least three observations for each NEA, with an observation period spanning July through December of 2022. Using a code written in Python, the Gauss Method orbital determination code implements the Monte Carlo method, generating 5000 samples to calculate the orbital elements with a reasonable level of error. When comparing these elements to the JPL Horizons tool, the average error of these preliminary results is less than 0.5%. At this time, only the lightcurve of asteroid 5626 Melissabrucker could be obtained, with a rotation period of (2.4856 ± 0.0002) hours, in accordance with the latest studies published in the MPC bulletin.
Denis Illesca and Andrés Piatti.
ABSTRACT: Determining the chemical composition of galaxies is essential to understand their structures and chemical evolution. One possible way to achieve this goal is to study the chemical composition of galactic star clusters through the color-magnitude diagram, this is because clusters are excellent tracers of the different subsystems that make up galaxies (bulb, disk, bar, halo). In order to carry out this analysis, it is essential to reliably characterize and identify the stars that are typical of clusters. In the present work we present a method of decontamination of stellar clusters that allows to identify the own stars of the cluster with a statistical assignment of membership for each one of them.
Hilver Adriano Castillo Calcedo, Isabel Tatiana Rodríguez Esnard, and Fernando Guzmán Martínez.
ABSTRACT: Hypercompact (HC) HII regions are, by nature, very young regions, associated with the earliest stages of massive star formation. They can host a single type B or type O star. Unfortunately, very few HC HII regions are currently known and are of vital importance as they represent a natural laboratory to study the physical processes involved in the formation of single star, without the complicating phenomena of a cluster environment. To improve the understanding of these regions, in this work we study the high-mass star formation region G53.04+0.11, a candidate for the HC HII region. In this way, we obtained maps of the continuum emission at G53.04+0.11 and determined some particular characteristics such as the size of the detected continuum sources, brightness temperature and spectral index.
Diana V. Lopez N. and Esteban D. Araya.
ABSTRACT: The dissipation of angular momentum of collapsing molecular cores is a key component in the formation of stars. Previous observations have reported that highly collimated protostellar jets can remove angular momentum from low-mass protostars. In contrast, the transfer of angular momentum in jets from high-mass protostars is not well understood. We report results of testing a data analysis platform using high-angular resolution observations of methanol and water masers to search for signatures of angular momentum in molecular jets. We find that high-angular resolution observations of masers near massive protostars have the potential of revealing this phenomenon at scales similar to the specific angular momentum carried by planets in our Solar System. We discuss specific examples, including ionized jet sources observed in the BeSSeL survey.
J. Thainá-Batista, R. Cid Fernandes & the S-PLUS team.
ABSTRACT: We present tests of a new method to simultaneously estimate stellar population and emission line (EL) properties of galaxies out of S-PLUS photometry. The technique uses the AlStar code, updated with an empirical prior which greatly improves its ability to estimate ELs using only the survey’s 12 bands. The tests compare the output of (noise-perturbed) synthetic photometry of SDSS galaxies to properties derived from previous full spectral fitting and detailed EL analysis. For realistic signal-to-noise ratios, stellar population properties are recovered to better than 0.2 dex in masses, mean ages, metallicities and ±0.2 mag for the extinction. More importantly, ELs are recovered remarkably well for a photometric survey. We obtain input − output dispersions of 0.05–0.2 dex for the equivalent widths of [O II], [O III], Hβ, Hα, [N II], and [S II], and even better for lines stronger than ∼ 5 A˚. These excellent results are achieved by combining two empirical facts into a prior which restricts the EL space available for the fits: (1) Because, for the redshifts explored here, Hα and [N II] fall in a single narrow band (J0660), their combined equivalent width is always well recovered, even when [N II]/Hα is not. (2)We know from SDSS that WHα+[N II] correlates with [N II]/Hα, which can be used to tell if a galaxy belongs to the left or right wings in the classical BPT diagnostic diagram. Example applications to integrated light and spatially resolved data are also presented, including a comparison with independent results obtained with MUSE-based integral field spectroscopy.
Ximena Cano Gómez and Esteban Silva Villa.
ABSTRACT: Defining the main features of the arms of a spiral galaxy remains an unsolved problem for modern astronomy. In previous studies, some authors have used different tracers to identify and measure the characteristics of the arms of different spiral galaxies, such as star clusters, Maseres, HII, among others. Recently, individual stars were used as tracers of the spiral structure in the Milky Way. One of the characteristics studied in the spiral arms is their width, which is usually estimated from 1 sigma around the mean of the data distribution of the spiral structure given by the tracer. In this work, the individual stars of the galaxy M83 (NGC5236) were used as a tracer of spiral arms and their width was measured from two methods: the traditional method of 1 sigma of the distribution, and from the study of the stellar density. In this work the following results were obtained: We found that the field of individual stars can trace the two spiral arms of the galaxy; we found a connection between the width of the arms and the galactocentric radius; and we found that the growth slope of the width of the arms could be correlated with the morphological type of spiral galaxies.
Ludving Cano and Gisela N. Ortiz-León.
ABSTRACT: When it comes to young low-mass stars (YSOs), studying the processes of proto stellar jet formation is of great importance, particularly focusing on early stages of evolution (class 0-I). This ongoing project aims to investigate the maser lines that serve as tracers of these jets, specifically observing them in the radio regime. We are specifically studying the conditions that give rise to the 22.2 GHz water maser line emission. Here, we study obtained using the Very Long Baseline Array (VLBA) of two stars where this emission got detected: CARMA 6 and CARMA 7 (both located in the Serpens South region) to explore whether this emission originates from the proto stellar jet, accretion disk, or both.